Electrical exchange system



(No Modem" 3 Sheets-Sheet' 1.

. G.. W. HEY 8v A. E. PARSONS.

ELECTRICAL EXCHANGE SYSTEM.

- N0. 533,893. Patented Eeb. 12. 1395'.

wnNx-:ssEs': l' IN mons Wwf/WMV.

ATTORN EY (No Model.) Y' 3 Sheets-Sheet 2.

G. W. HEY 8v A. E. PARSONS.

ELECTRICAL EXCHANGE SYSTEM Patented Feb. 12', 1895.

INVENTORS l BY ATTORNEY (No Model.) 1 a sneens-s'heet-.

G.'W. HEY & A. E. PARSONS.

ELECTRICAL EXCHNGB SYSTEM.

No. 533,893. Patented Peb. 12,'1895.

WITNESSES:

ATTORNEY l Unirse STATES PATENT Oratoire' GEORGE W. HEY AND ARTHUR E. PARSONS, OF SYRAOUSE, YORK.

' 'ELECTRICAL EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 533,893, dated February 12, 1895.

Application filed March 30, 1893.

To all whom it may concern: 2

Be it known that we, GEORGE W. HEY and ARTHUR E. PARSONS, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Electrical Exchange Systems, of which the following, taken in connection with the accompanying drawings, is a full, clear, and-exact description.

Our invention relates to improvements in electrical exchange systems for permitting communication between different metallic cir- Y cuits as telephonic, telegraphi'c, dac., and has for its object the production ota simple, practical, and eiective apparatus for accomplishing the desired result; and to this end it consists, essentially, all as hereinafter more fully described and pointed out in the claims.

In describing this invention, reference is had to the accompanying,r drawings, forming apart of this specit'lcation, in which like letters and numerals indicate corresponding parts in all the views.

Figure 1 is a diagrammatic view, illustrating'the general construction and arrangement of an apparatus embodying our improved system. Fi g. 2 is an enlarged diagrammatic view of the main station. Fig. 3 is an elevation of one of the detached switching devices. Fig. 4 isa similar elevation, the movable support for the movable terminalbeing removed and shown by dotted lines. Fig. 5 is a top plan View of the switching device shown at Fig. 2, the support for theterminals connected to the separate Wires being shown in section, and Fig. 6 isa detailsectional view, taken on line 6 6-, Fig. 3.

A A20, B B20, C C20, D D20, represent the wires or conductors of a series of separate metallic circuits; a, b, c, d, automatic switching devices connected to the ends of the conductors' A A20, B B20, C C20, D D20, and E a series of ground wires having branches e c', e2 e2 con'- nected respectively to the switching devi-ces a, b, c, cl. The Wires E and the switching devices ct, b, c, d, are preferably arranged at a main or common station E', and the WiresA l .A20,B B20, O O20, D D20 extend from the main station E to a series of subscribers stations A B C D D"D D.

p As clearly seen at Eig. 1 we have illustrated a number of the stations D arranged one af- Serial No. 468.374. (No model.)

ter the other for forming sub-stations for the Wires D D20. The extreme outer end of the Wire D is connected by a branch D2 to the ground, and the inner ends of the Wires A20, B20 C20 D20 are, as presently described, normally connected to the ground Wires E of the common or main station.

When our invention is used as a telephonie electrical exchange system the stations A B O D D D D are provided With Ytelephones A20 B20 C20 D20 D20 D20 D20 connected to loops A21 B21 C21 D21 D21 D21 D21, which are connected by switches A22 B22 O22 D22 D22 D22 D22 to the metallic circuits leading fromrsaid stations, but it is unnecessary to illustrate or describe said telephones in detail, as their construction' forms no essential feature of our present invention.

The stations A' B C D D DD E are respectively provided with a series of signals A2 B2 O2D2 D2 D2 D2 E2 and with a series of current generators A4 A5, B4 B5, O4 C5, D4 D4 D4 D4, D5 D5 D5 D5, E4 E5, for eiectingfthe operation of said signals, all of which parts may be of any desirable form, size, and construction.

The signals A2 B2 C2 consist of magnetoelectric bells, and the current generators A4 B4 C40 D4 D4 D4 D4 E4 for operating said bells preferably consist of alternating-current generators, the generator E4 being a dyn-amo electric machinefor producing an alternating current and the other generators being magneto-electric machines.

The signalsD2 D2 D2 D2 preferably consist of automatic electric bells, and the generators A5 B5 C5, D5 D5 D5 D5 E5 for effecting the action of said signals consist of direct currentgenerators, which are here indicated as batteries, although it is evident that the generator E5, and, if desired., any of the other generators may consist of a dynamo-electric machine for producing a direct current.

The signals A2 B2 C2 are connected to the wires A20 B20 C20, and are connected by short Wires A0B6 C2 to the generators A1 B4 O4, and the Wires A B O are connectedto said generators, and to the outer ends of ground Wires All. B11 C11l 5 v The generatorsr A5 B5 C5 are connected to the ground by short Wires A8 B8 C2 provided with suitable calls 10,. and are connected by ro n wires A0 B0 C0 to the wires A20 B20 C20. The calls 10 normally break the circuits from the generators or batteries A5 B5 C5130 the ground, and, when operating, permit the passage of a series of consecutive current pulsations from said generators through the wires A5 B5 C5 to the ground and also through the wires, A2O B20 C20 to the switching devices a, b, c, (Z, and thence, as presently described, to the wire D20 and to the ground through the ground wire D2.

The signals D3 D5D5D2 of the substations D D DD, which,as previously stated, preferably consist of automatic electric bells, are each connected by positive and negative wires D5 D7 to local generators or batteries D15 D15 D15 D15, and each pair of said wires D5 D1 is connected to a circuit closer D5 for normally breaking the circuit through said wires and preventing the operation of the corresponding signals D5.

The circuit closers D5 D5 D5 D5 are each connected by wires D0 D10 to the line wire D20, and are so constructed as to be automatically operated by the passage through said line wire of predetermined current pulsations from the generators or batteries A5 B5 (l5, D5 D5 D5 D5 E5. These circuit closers may be of any desired construction, providing they are so arranged as to be operated independently by predetermined current pulsations in order that any one circuit closer may be operated to close the local circuit from the battery D15 without effecting the similar operation of the others. Consequently by the passage of a predetermined number of current pulsations through the wire D20 any one cf the circuit elosers D5 D0 D5 D5 is operated at will to close a local circuit for actuating the signal D3 of the station provided with said circuit closer` and the signals of no two of the stations D D D D are operated simultaneously. i

In the pending applications, Serial Nos. 430,274 and 432,254, of George W. Hey there are shown circuit closers capable of being independently actuated, as described, by the passage of predetermined current pulsations through the line wire connected therewith, and consequently we do not deem it necessary to herein further illustrate and describe said circuit closers, since the circuit closers described in said applications may be used if desired.

The wires D9 D10 of cach station D D D' D are provided with a switch D11, and the generators D5 D5 D5 D5 are connected to the corresponding switches D11 D11 D11 D11 by wires D12 D15, D12 D15, D12 D15, D12 D15. Each of said switches D11 D11D11D11 is so constructed as to normally pass the current through the wires D0 D10 from the lwire D20 to the corresponding circuit closer, or to pass the current at will from the generator D5 through the wires D12 D15 to the line wire D20. A suitable call D11 is connected to each of the wires D13 for normally breaking the circuit through said wire and controlling the current pulsations passed therethrough from the corresponding generator D5 to the line wire D20.

The current generators D1, as previously stated, preferably consist of magneto-electric machines, and are each connected to the lino wire D20 by branch wires D10 having their upper ends provided with a switch D17 for normally connecting said upper ends and permitting the ready passage through the line wire D20 of current pulsations from the generators A5 B5 C5, D5 D5 D5 D5 E5, and pre venting the retardment of the transmission of sound by the generators D1 D1 D1 D1, and the signals as magneto-electric bells D12 D15 D15 D12 in circuit with said generators.

The signals E5 of the main station E are in circuit with the wires E, and these signals, although illustrated as magneto-electric bells, may consist of visual signals in order that the attendant may readily and conveniently receive the signal.

In practice, as presently described, each of the line wires A20 B20 C20 is connected normally to one ot' the wires ofthe main or common station E.

The generators E1 of the main station are connected to separate branches of a grounded wire E2, and are also connected to wires E5 E11, which terminate at switches E10 upon the wires E connected to the branch wires e e', c2 e0 leading from the switching devices a, 19,0, d. These switches E10 are so constructed as to nor mally permit the passage of the current from the generators A1 B1 C1 D1 D1 D1 D1, line wires A20 B20 C20 D20, and switching devices a b c d through the branch wires e e', e2 e5, to the signals of the wires E, and to also prevent the passage of a current through said wires E when desired to pass the current from either of the wires E5 E2 through said branch wires to the signals A5 B3 C5 D5 D3 D5D0of themetallic circuits connected therewith.

The main station E is provided with one or more telephones E20 connected to loops E21 having corresponding ends terminated at switches E52 for connecting the same to the branch wires c c', e2 e5, and having their opposite ends connected to the wires A, B, C, D. The wires E of the main or common station are independently grounded at the main station, as previously stated, and the line wires A20 B20 C20 D20 are provided with switches A21 B21 C21, D21 D21 D21 D21 in proximity to the generators A1 B1 C1D1 D1 D1 D1 connected thereto. These switches form normally a part of the metallic circuit extending from the stations A B C D', and normally permit the passage of the current through the wires A A20, B B20, C C20, D D20, but said switches may be connected to the adjacent ends of local ground wires A22 B22 C22 D22 D22D22 D22 at the stations A B C D D' D D' for grounding the generators A1 B1 C1 D1 D1 D1 D1 at said stations.

When the subscriber at one of the stations A B C D' D' D D desires to signal the main station he connects to the aforesaid local IOO IIO

ground wire of his station the generator at said station adapted to vactuate the corresponding signal of the main station, and connected thereto by one of the line wires. He

5 then readily actuates the signal of said main station by the operation of said generator,

using the local ground wire, said line'wire, and the wire E as the circuit.

As soon as a signal of the main station is actuated, as previously described, by any one of the current generators A4 B4 G4, D4 D4 D4 D4 of the stations A B C D D D D lthe person atthe subscribers station'breaks the local ground connection by means of the tendant at the main station in charge of said signal, and the person at the subscribers station immediately connectinto circuit the telephones at said stations. On the contrary, if it is desired without the aid or even without the knowledge of the central station to operate by the current generator of one of the stations A B C D D D D the signal at another of said stations, the switching-device at the main station connected to the wires forming the metallic circuit leading from said station is operated, as presently described, to connect said circuit with the metallic circuit leading from the station providedwith the signal that it is desired to operate, and said current generator is then in circuit with and free to actuate said signal. It will be understood, however, that, if it is ldesiredto operate the signal of one of the sub-stations D D D D by the subscriber at one of the stations-A B C that the directeurp rent producing generator of the subscribersV station is connected to the correspondingline wire of the metallic circuit leading therefrom by the corresponding switching device at the main station for effecting said result, and that, by means of the call l0 connected to the ground wire of said generator, the necessary current pulsations are passed through said line wire-and its corresponding switching device to the line wire D20 and through the circuit closers D0D0D2 D2, whereupon the' circuit closer connected to the signal, which it is desired to operatc,is actuated to permit the passage of the local current to said signal, and the desired local signal is operated without-bringing into action any of the signals of the other stations D.

In order that our invention may be more thoroughly understood let it be supposed that the attendant at the station A desires to act- Y uate the signal B2', the switching device ct is operated, as presently described, to connect the wires A A20, B B20, and upon the action of the-magneto-electric machine or other current generator A4 at said station A', the signal B3 normally in circuit with the wires B B20 is immediately operated. The persons at said station then connect the telephones A20 B20 into circuit bymeans ofthe switches A22 B22, and said telephones are thenconnected Y together by acomplete metallic circuit. Let

switch therefor, as just described, and the atit also be supposed that the subscriber at station A desires to operate the signal D3 at one of the stations D. The wire A20 is con- 2 nected to the Wire D20 by the switching device d,cu rrent pulsations from the generator A5 are passed through the wire A20 by means of the call l0, and are then passed through the switching device a and the wire D20 for operating the circuit closer D8 connected to said signal D?, and immediately said signal is actuated bythe local current generator D15. The telephones A30 D20 are then connected by the switches A32 D32 to the metallic circuits leading from said stations A D.

As the wires A20 B20 C20 D20 are normally in circuit with the corresponding Wire E, as previously described, the attendant-s at the main station E are able to call any of the stations A B O by operating the switches E10 to connect the currentgenerator Etinto circuit with the branch wires e c e2 extending to the switching devices a b c connected to the circuits leading from said main station, and said attendants are also enabled to call any of the substations D D D D by similarly connecting the generatorE5 to the branch Wire c3 extending to the switching device d connected to the line wire D20 of the metallic circuit extending to thev stations D D D D and by passing through said line wire D20 the required current pulsations for operating the circuit closer at the station which itl is desired to call.

At Figs. 3 to 6 inclusive we have fully illus'- trated the switching device a, which is similar to the remaining switching devices h c d, and is only indicated in the previous figures. This ICO switching device consists of a support ct preferably formed of insulating material, a series of terminals l, 2, 3, 4, mounted on said support, a movable terminal a2 for making contact with the terminals l, 2, 3, 4, a movable support a2 for moving the terminal a2, and an armature lever a4 connected to actuate the terminal support c3.

The terminals 1,02, 3, 4, of the switching device d, are clearly indicated at Figs. l and 2, and, as seen therein, and at Figs. 4 and 5, the terminal 1 is connected by the branch wire e to the corresponding wire E, and the terminals 2, 3, 4, are respectively connected by comparatively short branch wires 2 3 4 atthe main station to the wires B20 C20 D20. The armature lever a4 of the switching device ct is provided with a suitable feeding dog a5 which engages a series of teeth in the edge of the movable support a3, and said lever is provided with a stop dog a0 for engaging the teeth of said support a2 and preventing the feeding of said support more than a tooth at a time. A suitable stop dog as a7 prevents the retrograde movement of the support a2.

IIO

The lever a4 is drawn forwardly by a magnet a8, presently described, and, as the current is broken which energizes said magnet, a suitable retractor as a spring a0 returns the armature lever to its normal position. The

movable .terminal support d3, thel armature i teased lever a, and the dogs a0 a0 a2 are so arranged that the action of the magnet a2 only draws the feeding dog a5 into operative position, and the action of the retractor a0 restores the feeding dog to its normal position and feeds the disk a tooth at a time. rlhis is a particularly practical and effective construction of step by step movement, since the same is not in the least dependent upon the strength of the current energizing the magnet a0, providing said current is sufficiently strong to cuable the magnet to draw the armature lever a* to operative position, and consequently the feeding of the disk is very uniform and accurate. Itis desirable, however, to provide an adjuster d20 for the spring a0, and since this may be of any desirable form, size, and construction, we have shown the same as consisting of a revoluble pin for supporting one end of the spring a0.

The wire A20is connected to the shaft allot the movable supporta2 of the switching device a, and one end of the movable terminal a2 of said switching device is connected by the movable support a2 to said shaft au, and the opposite end of the terminal (L2 normally makes contact with or engages the terminal l,thereby normally connecting the wires A20E.

As the support a0 is moved or rotated by the oscillatory movement of the armature lever a4 occasioned bythe action of the magnet c2, presently described, the free end of the terminal a2 makes contact successively with the terminals 2, 3, and 4, and by means of the branch wires 2 3 4' extending trom said terminals the wire A20 is successively connected to the wires B20 C20 D20. It will be readily understood that the support a may be provided with a greater number ot' terminals than illustrated, and that the wire A20 may be connected successively by the switching device a. to all of the wires connected to the terminals of said support a.

The switching devices a, b, c, d, are all of similar construction, and consequently it is unnecessary to illustrate in detail the remaining switching devices b, c, d. We have, however, indicated at Figs. l and 2 the terminals 1, 2, 3, 4 of the switches b, c, d, and, as clearly shown at said iigures, the branch wires e c2 e2 connect the corresponding wires E to the terminals l of the switching devices l), c, d.

The terminals 2, 3, 4 of the switching device b are connected by the respective wires 2 3 4 to the wires C20 D20 A20. The similar terminals of the switching device c are connected bythe branch wires t2 3 4 to the wires D20 A20 B20, and the terminals 2, 3, 4 of the switching device d are connected by the branch wires 2 3 4' to the wires A20 B20 C20. XVe have also illustrated at said Figs. l and 2 the armatures and shafts h4 c4 d4, l1 c d of the switching devices b cd, and, as clearly seen at said figures, the wires B20 C20 D20 are respectively connected to said shafts, and we have indicated in said figures the actuating magnets b2 c2 d0 for said switching devices. In orderto facilitate secureincnt of the branch Wires 2 3 4 of the switching devices u., b, c, d, to the wires A20 B20 C20 D20, said wires, A20 B20 C20 D20 are provided at the station E with laterally extending branches only one of which is connected to the corresponding switching device. It will thus be readily understood that the initial or zero terminal l of cach of the switching devices a l) c d is normally connected to one of the line wires ot' the metallic circuit for thesubscribers station corresponding to said switching devices and to the corresponding wire E at the main or common station, and that the remaining terminals of each of said switching devices are connected respectively to the corresponding line wires of the separate metallic circuits extending from the main station.

The ends of the wiresA B C D at the main station E are connected to the actuating magnets a8 D0 c8 d0 for controlling the operation of the switching devices, and are also connected to a common wire E20 having one end extended to a battery E21 grounded by a wire E22.

In order that the action of said switching devices may be entirely under the control of the persons at the stations oi' the branch wires, a call 5 is connected to each of the ground wires A B11 C11 previously mentioned, and to local ground wires D10 D10 D10 D10 at the stations D D D D connected to the wire D, and, when said calls 5 are actuated, a series of current pulsations are passed from the battery E21 through the wires A B C D to the ground, and serve to energize the magnets a0 bs c8 d2 and rotate the movable terminals a2 b2 c2 d2 of the switches a. b c d. It will be understood, however, that each of these calls 5 operates independently, and that consequently each magnet a8 190 c2 d0 is operated independently. These switching devices and calls are so relatively constructed thatthe complete action ofthe call causes the movable terminal a2 of the switching device connected to said call to make a complete revolution, and said calls are also so constructed that, after one has rotated the movable terminal of the switching device connected thereto into engagement with the predetermined terminal of the switching device, the movable parts of said call are temporarily restrained from movement by a suitable stop pin or other device not necessary to herein illustrate or further describe. Said movable terminal then remains in this position until the movable parts of said call are again permitted to continue their movement and the movable terminal then completes its revolution and normally connects to the corresponding wire E, the line wire provided with said call. We have not deemed it necessary, however, to more than indicate the calls 5 at Figs. l and 2, since their detail construction and arrangement form no part of our present invention, and since it is well known to those skilled in the ICO art that a call may be operated to send through a line connected thereto any determined nurnber of pulsations, and may in its movement evident to one skilled in the art, and, as the detail construction thereof forms no part of our present invention, it is unnecessary to further illustrate or describe the same.

It will thus be readily understood that the subscriber upon any of the wires A B C D is normally connected with the corresponding line E of the main station E', and can either signal said station directly for any purpose whatever as to secure connection to an out of town line, or can at will by means of his automatic switching device, automatically connect himself with any of the other lines connected to his automatic switching device, and

,call the attention of the attendant at the subscribers station of any of said wires by operating his magneto electric, machine in the ordrnary manner, and can effect this operation wlthout the aid, or indeed without the knowl edge of the attendants at the central station or the knowledge or inconvenience of the subscribers of the otherline'wires.

The normal, connection of the wires E of the main station to all of the line wires leading from the main station enables the attendants at the main station to test the line wires in the usual manner.

The feature of great advantage of our system is that when -the subscribers on any of the line wires are connected either to the central station or to the other line wires for talking therewith that complete metallic circuits connect the telephones at said stations, and, in order that these circuits may-be more readily apparent, we will now proceed to briefly describe the same.

Let it be supposed that the subscriber at station A has signaled one of the attendants at the main station, and that said subscriber and the attendant have placed the switches A32 E32 so as to connect the telephone A30 to the wires A A20 and the telephone E30 to the branch wire e and the loop E33. The metallic circuit connecting the telephones A30 E30consists of the wire A20, movable terminal a2, normal terminal 1 of the switching device a, branch wire e connected by the switch E32 to the loop E3l provided with a telephone E30, and the wire A connected to the loop A31 provided with a telephone A30, On the other hand if the subscriber at station'A has signaled the subscriber at one of thesub-stations D D', and said subscribers have placed their switches A32 D32 so as to connect-the telephones A30 D30 to the wires A A20 D D20;

minal 4 of said switching device, branch wire 4', wire D20, loop D31 connected to the wire D20 and provided-with the telephone D00, wire D, main station wire E20, wire A, and the loop A31y provided with a telephone A30.

It is thus apparent from the foregoing description that the telephones of our exchange are connected together by metallic circuits when in use; that corresponding wires of each circuit are normally connected together by the main station wire E20, and that the opposite wires of said circuits are normally connected to grounded wires at the main station, and are automatically connected together by the corresponding switching devices.

It will also be evident 'that each station upon the line wires is provided with a ground wire adapted to be connected to one of the wires of t-he metallic circuit leading therefrom for operating the signal at the main station, andis also provided with an additional ground .wire provided with a call and connected to the other wire of said metallic circuit for operating the corresponding switching device at the main station, which is controlled by a magnet connected tosaid wire.

Our invention will be readily understood upon reference to the foregoing description and the accompanying drawings, and it will be evident to one skilled in the art that it is particularly simple, practical, and effective connected to the various metallic circuits leading from said station, and the exact arrangement of Wiring at the main and subscribers stations may be considerably changed or varied without departing from the spirit of our invention, and hence we do not herein'specifically limit ourselves to the exact detail, construction and arrangement of said parts.

. Having thus fully describedour invention, what we claim as new, and desire to secure by Letters Patent, is f 1. An electrical exchange system, the same consisting of a series of metallic circuits, and an automatic switching device suitably connected in said circuits and provided with means operated by electric currents passed over one of the wires of said circuits, whereby,

'one of said circuits is connected to any of the others, substantially as and for the purpose described.

2. An automatic electrical exchange system comprising a series of metallic circuits, each circuit being provided with an automatic switching device connected in one conductor thereof and each switching device being provided with connections to corresponding conductors of the remaining circuits, and a movable member connected to said conductor of each metallic circuit, and means operated by electric currents passed over one of the wires of the metallic c ircuit connected with said switching device vfor connecting said movable member to said connections, whereby one cir- IOO Iig

cuit is connected to any ot the others, substantially as specified.

3. An automatic electrical exchange system comprising a main station, a series of metallic circuits converging at said main station and having corresponding conductors connected together, each circuit being provided with an automatic switching device connected in the oth er conductor thereof and each switching device being provided with connections to corresponding conductors of the remaining circuits, a movable member connected to the other conductor of the metallic circuit connected with said switching device, and means operated by electric currents passed over one of the wires of said metallic circuit for connecting said movable member to said connections, whereby one circuit is connected to any ot the others, substantially as and for the purpose described.

4. In an electrical exchange system, the "combination of a series of metallic circuits, each provided with a suitable transmitter and receiver, and an automatic switching device suitably connected in said circuits and provided with means operated by electric currents passed over one of the wires of said circuits, whereby one of said circuits is connected to any of the others, substantially as and for the purpose set forth.

5. An automatic electrical exchange, the same comprising a series ot metallic circuits, sub-stations for one of said circuits, an automatic switching device connected in the circuit provided with the sub-stations and connected to the other circuits, and provided with means operated by electric currents passed over one of the wires ot said circuit whereby said circuit is independently connected to the other circuits, and means at each sub-station for controlling the action of said automatic switching device, substantially as and for the purpose specified.

G. In an electrical exchange system, the combination of a series ot metallic circuits each provided with transmitting, receiving, and signaling devices, and an automatic switching device connected to said circuits and provided with means operated by electric currents and connected to one of said circuits; whereby the operations of said switching device and said devices ot the circuits connected by said switching device are effected by electric currents passed over said metallic circuits, substantially as set forth.

7. An electrical exchange system, the same comprising metallic circuits having correspending wires normally connected together and their opposite wires normally disconnected, and an automatic switching device operated by current pulsations passed over one of the wires of said circuits for connecting said opposite wires together, substantially as and for the purpose specified.

8. An electrical exchange system,the same comprising metallic circuits having corresponding wires normally connected together and their opposite wires normally disconnected,wires as E normally connected to the disconnected wires of the metallic circuits, an automatic switching device connected to said metallic circuits and operated by electric current pulsations passed over the wires ot' said `circuits for connecting and disconnecting the normally disconnected wires thereo l", substantially as and for the purpose set forth.

9. An electrical exchange system, the same comprising a series of metallic circuits, an automatic switching device suitably connected to said circuits and operated by current pulsations passed overone ofthe wires of the circuits for connecting one of said circuits to any one of the others, and a call for controlling the action of said switching device substantially as and for the purpose set forth.

10. An electrical exchange system, the same comprising a series of metallic circuits, an automatic switching device connected in one of said circuits and operated by current pulsations passed over one of the wires of y said circuits and connected to the other circuits, whereby said one of the circuits is automatically connected to the other circuits, a signal normally in circuit in one of said circuits, and means connected to another of the circuits for operating said signal, substantially as and for the purpose set forth.

11. The combination in an electrical exchange of a series of metallic circuits, a series of telephones connected to the circuits, an automatic switching device connected in one of said circuits and operated by current pulsations passed over one of the wires ot said circuits and independently connected to the other circuits, whereby the telephone connected to said one ot the circuits is automatically connected to the other circuits, a signal in one ot' said circuits, and means connected to another of the circuits for operating said signal, substantially as and for the purpose described.

12. The combination in an automatic switching device; of a series of fixed terminals con nected to a series of line wires of independent metallic circuits, and a pair of line wires forming a metallic circuit, one wire ot' said pair being connected to a movable terminal of said switching device and the other wire being connected to actuate said movable terminal, whereby the metallic circuit formed by said pair of wires may be connected to any one of the other independent metallic circuits through the medium ot currents passed over the other wire of said pair, substantially as and for the purpose described.

13. The combination in an automatic switching device connected to a metallic circuit; of a series of fixed terminals and one movable terminal, an electrounagnet connected to one of the wires of said metallic circuit, mechanism connected to the movable terminal and operated by said magnet for connecting the movable terminal with any one of the fixed terminals, and a series ot wires of independ- IXO ent metallic circuits connected to said fixed terminals whereby the metallic circuit connected to said switching device is automatically connected by said switching device to said series of metallic circuits, substantially as and for the purpose described.

14. In an automatic electrical exchange system, the combination of a main 4station having one or more signals, a series of metallic circuits leading to the main station, one wire of each circuit being normally connected to a signal at the main station, ground Vconnections for the opposite ends'of said wires, a series of switching devices at the main station for connecting the former wires to each other t at the main station, magnets at the main station, connected to the latter wires and to said switching devices for operating the same, and mechanism at the opposite ends of the latter wires for controlling the action of said magnets, substantially as and for the purpose dey scribed.

15. The combination of the wires of a pair of metallic circuits; with an automatic switching device connected to one of said wires and provided with means for connecting said me signed our names, in the presence of two attcsting witnesses, at Syracuse, in the county of Onondaga,l in the State of New York, this 16th day of March, 1893.

GEORGE W. HEY. ARTHUR E. PARSONS.

. Witnesses:

CLARK H. NORTON, E. A. WEISBURG. 

